1. Field of the Invention
This invention relates to an ophthalmic measuring apparatus, and more particularly to an ophthalmic measuring apparatus for effecting optical measurement of the shape of the cornea and measuring the lengths of various portions of an eye to be examined such as the thickness of the crystalline lens, the length of the vitreous body and the length of the eye axis by the use of an ultrasonic wave.
2. Related Background Art
Heretofore, spectacle lenses or contact lenses have been used for the correction of the refractive power of the eye after an operation for a cataract, but in recent years, it has become the practice to insert an in-the-eye lens into the position of the removed crystalline lens. To choose an in-the-eye lens proper for a patient having an eye having no crystalline lens, it becomes necessary to know the refractive power of the cornea and the length of the eye axis (the length from the cornea to the retina).
Heretofore, however, there has been the inconvenience that measurement of the refractive power of the cornea must be effected by a cornea shape measuring apparatus and measurement of the length of the eye axis must be effected by a separate ultrasonic measuring apparatus, whereafter the refractive power of the in-the-eye lens must be calculated. Also, much time has been required because alignment with the eye to be examined is effected by each of the measuring apparatuses.